The present invention relates to a surgical jawed instrument.
Jawed surgical instruments of this kind are fitted with electrodes fitted at one or both of the jaw parts to apply high frequency (hf) power in single or double polar application to a tissue being cut or gripped in order to seal it by hf current. Such jawed instruments can be disassembled for cleaning.
With jawed instruments of this kind, as disclosed in the German patent document DE 94 18, 094 U, the jaw head may be locked at the distal stem end and, following unlocking, may be jointly pulled out with the actuation bar of said stem. In the process, the actuation bar is pulled distally through the tubular stem. Because the actuation bar always must be pulled through the stem tube and because a contactor is affixed to the end of the cable and cannot be pulled through the stem tube, in the relevant state of the art and also in similar jaws such as disclosed in the German patent document DE 298 23 913 U1, the cable can only be connected to the actuation bar's proximal end by a complex plug-in connection. Such a connection however is susceptible to malfunction and/or interference due to high load transmission of hf current and entails disadvantageous capacities and transition resistances adversely affecting the hf current circuit. These electrical connections in particular entail difficulties when hf generators are used that measure the tissue impedance during hf electrode loads for purposes of current control. Interfering impedances and capacitances in the connection are likely to entail spurious impedance measurements.
Jawed instruments outside the above species, such as disclosed in WO 2005/004735 A1, are more suitable, namely their cable runs uninterrupted through the full stem length and is directly connected to the electrode. However such instruments cannot be taken apart for cleaning and accordingly, are appropriate only for single use. Repeated use being precluded, the use of such instruments is very expensive.